tools/virtio: use {READ,WRITE}_ONCE() in uaccess.h

As a step towards killing off ACCESS_ONCE, use {READ,WRITE}_ONCE() for the
virtio tools uaccess primitives, pulling these in from <linux/compiler.h>.

With this done, we can kill off the now-unused ACCESS_ONCE() definition.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/tools/virtio/linux/uaccess.h b/tools/virtio/linux/uaccess.h
index 0a578fe18653..fa05d01b2c90 100644
--- a/tools/virtio/linux/uaccess.h
+++ b/tools/virtio/linux/uaccess.h
@@ -1,8 +1,9 @@
 #ifndef UACCESS_H
 #define UACCESS_H
-extern void *__user_addr_min, *__user_addr_max;
 
-#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
+#include <linux/compiler.h>
+
+extern void *__user_addr_min, *__user_addr_max;
 
 static inline void __chk_user_ptr(const volatile void *p, size_t size)
 {
@@ -13,7 +14,7 @@ static inline void __chk_user_ptr(const volatile void *p, size_t size)
 ({                                                              \
         typeof(ptr) __pu_ptr = (ptr);                           \
         __chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr));            \
-        ACCESS_ONCE(*(__pu_ptr)) = x;                           \
+        WRITE_ONCE(*(__pu_ptr), x);                             \
         0;                                                      \
 })
 
@@ -21,7 +22,7 @@ static inline void __chk_user_ptr(const volatile void *p, size_t size)
 ({                                                              \
         typeof(ptr) __pu_ptr = (ptr);                           \
         __chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr));            \
-        x = ACCESS_ONCE(*(__pu_ptr));                           \
+        x = READ_ONCE(*(__pu_ptr));                             \
         0;                                                      \
 })